Quick summary

Magnesium citrate is a compound of magnesium combined with citric acid that is commonly used as a dietary supplement to provide magnesium, an essential mineral involved in many physiological functions.

What is it?

Magnesium citrate is a salt formed by magnesium and citric acid. As a supplement, magnesium citrate provides a bioavailable source of magnesium, which is required for numerous metabolic processes in the body. It is one of several forms of magnesium salts used for dietary supplementation and is often preferred due to its relatively good absorption compared to other magnesium compounds.

Main functions in the body

  • Supports normal muscle and nerve function
  • Contributes to energy metabolism
  • Maintains normal bone structure
  • Participates in DNA and protein synthesis

Recommended intake and upper limit

The recommended daily intake of magnesium varies by age, sex, and life stage. For adults, typical intake levels range from approximately 310 to 420 milligrams per day from all sources combined (diet and supplements). Tolerable upper intake levels (UL) for magnesium obtained from supplements are generally set around 350 mg/day, which aims to minimize adverse effects, especially gastrointestinal discomfort.

Those pregnant or breastfeeding, as well as individuals with specific health conditions, should consult healthcare professionals about their magnesium requirements.

Parameter Summary
RDA / AI 310–420 mg/day for adults (varies by age, sex, life stage)
Upper Limit (supplements) 350 mg/day to reduce risk of adverse effects

Best food sources

Magnesium from dietary sources is readily absorbed and contributes to maintaining adequate magnesium status. Foods rich in magnesium include:

  • Green leafy vegetables
  • Nuts and seeds
  • Whole grains
  • Legumes
  • Some fish varieties

Deficiency: causes, symptoms and risk groups

Magnesium deficiency is uncommon in healthy individuals consuming a varied diet but may occur in specific clinical situations or with sustained insufficient intake. Risk groups include:

  • Individuals with gastrointestinal disorders causing malabsorption
  • People with chronic alcoholism
  • Older adults
  • Those with poorly controlled diabetes

Signs and symptoms potentially associated with magnesium deficiency include:

  • Muscle cramps
  • Fatigue
  • Irritability
  • Abnormal heart rhythms

Supplement forms

Magnesium citrate is a commonly used form of magnesium supplement known for its relatively good bioavailability when compared to some other magnesium salts. It is available in tablets, capsules, powders, and liquid formulations. Other magnesium supplement forms include magnesium oxide, magnesium bisglycinate, magnesium sulfate, and more, but distinctions should be made based on scientific evidence where available.

Absorption and bioavailability

Magnesium citrate is generally well absorbed in the gastrointestinal tract relative to several other forms of magnesium supplements. Bioavailability can vary depending on dietary factors, individual health, and supplement formulation.

Specifically:

  • Magnesium citrate tends to have higher bioavailability than magnesium oxide.
  • Absorption may be influenced by gastrointestinal health and presence of other nutrients.

Potential benefits: what does the evidence say?

The strongest evidence for magnesium citrate supplementation supports its effectiveness in correcting magnesium deficiency. Supplementation with magnesium citrate has been shown to increase serum magnesium levels in individuals who are deficient.

Evidence specific to magnesium citrate outside of correcting deficiency is limited. There is a lack of comprehensive clinical trials comparing long-term outcomes of magnesium citrate supplementation with other magnesium forms or placebo in otherwise healthy populations. Therefore, claims regarding broader benefits should be viewed cautiously.

Side effects and toxicity

Magnesium citrate supplementation is generally regarded as safe when used within recommended doses. Common side effects are usually mild and primarily gastrointestinal, including:

  • Diarrhea
  • Abdominal discomfort

Excessive intake of magnesium supplements above the upper intake level (around 350 mg/day) is associated with increased risk of these adverse effects. Rarely, serious toxicity can occur, particularly in individuals with impaired kidney function, since the kidneys play a key role in regulating magnesium levels.

People with kidney failure or other kidney impairments should only use magnesium supplements under medical supervision.

Drug and nutrient interactions

No specific interactions between magnesium citrate and medications are supplied in the current evidence dataset. Generally, magnesium supplements can affect absorption of certain medications such as antibiotics and bisphosphonates; similarly, some drugs may affect magnesium status. Individuals on medication should consult healthcare providers before starting supplementation.

Who should be careful?

  • Individuals with kidney failure or impaired kidney function
  • People with known magnesium metabolism disorders
  • Those who are pregnant or breastfeeding should consult healthcare professionals for personalized advice
  • Individuals taking medications known to interact with magnesium or affect kidney function

Frequently asked questions

Is magnesium citrate better absorbed than other magnesium supplements?
Magnesium citrate generally has better absorption compared to magnesium oxide, but individual responses may vary depending on health status and diet.
Can magnesium citrate supplements prevent heart disease or improve energy?
Current evidence does not support magnesium citrate supplements for preventing heart disease or enhancing energy in healthy individuals. Supplementation is primarily effective for correcting magnesium deficiency.
What dose of magnesium citrate is safe to take?
The tolerable upper intake level for magnesium from supplements is generally about 350 mg/day. Higher doses may cause gastrointestinal side effects. Consult a healthcare provider for personal recommendations.
Are there any risks with magnesium citrate supplementation?
Magnesium citrate is usually safe but can cause diarrhea at high doses. Those with kidney disease should use it cautiously and under medical advice.

Evidence limitations

  • There is limited data specifically comparing magnesium citrate to other magnesium supplement forms regarding long-term clinical outcomes.
  • No comprehensive clinical trials were supplied for magnesium citrate supplementation outside the context of correcting magnesium deficiency.
  • EU-authorized health claims for magnesium citrate are not provided in this dataset.

References

Disclaimer: This information is provided for educational purposes and does not constitute medical advice. Individuals who are pregnant, breastfeeding, have medical conditions (including kidney or thyroid disorders), iron overload disorders, or take medications should consult a healthcare professional before starting any supplement regimen.

Last reviewed: June 2024